West Haven, CT: The intravenous administration of cannabis’ primary psychoactive compound, delta-9-THC, poses a "relatively low" risk to subjects’ health, according to a review of clinical trial data to be published in the journal Psychopharmacology.

A team of investigators at the West Haven, Connecticut branch of the US Department of Veteran Affairs conducted a review of all intravenous THC studies conducted at the center over a 13-year period. They assessed 11 studies involving 266 subjects (14 schizophrenia patients and 252 healthy subjects, of whom 76 were frequent cannabis users), 351 active THC infusions, and 226 placebo infusions. Study subjects were monitored for subjective and physical adverse events and followed up to 12months beyond study participation.

Authors reported: "There was one serious and 70 minor adverse events in 9.7 percent of subjects and 7.4 percent of infusions, with 8.5 percent occurring after the end of the test day. Nausea and dizziness were the most frequent side effects associated with intravenous THC administration. Adverse events were more likely to be associated with faster infusion rates (two to fiveminutes) and higher doses. Of [the] 149 subjects on whom long-term follow-up data were gathered, 94 percent reported either no change or a reduction in their desire to use cannabis in the post-study period, 18 percent stated that their cannabis use decreased, and three percent stated that it increased in the post-study period."

Researchers concluded: "With careful subject selection and screening, risk to subjects is relatively low. Safeguards are generally sufficient and effective, reducing both the duration and severity of adverse events."

Commenting on the study, NORML Deputy Director Paul Armentano said, "This review once again reaffirms the cannabis is relatively safe, if not safer, than comparable conventional medications or intoxicants. The plant’s relatively low toxicity and risk to health in no way justifies the continued criminalization and arrest of hundreds of thousands of cannabis consumers annually."

For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, "The safety of studies with intravenous delta-9-tetrahydrocannabinol in humans, with case histories," appears online in the journal Psychopharmacology.